For the placing of flat covering pieces such as ceramic pieces, tiles and other similar with a substantially uniform thickness on the floor, walls or other substrates, a holding layer of mortar or adhesive is used on which the covering pieces are located. This operation requires a certain precision from the side of the operator in order that afterwards the surface which bears the covering pieces shows a smooth and sufficiently level finishing. This process is annoying and time consuming. Each of the pieces has to be placed, leveled and left flush with the adjacent pieces already placed, in an individual and completely artisanal form.
The process has to be carried out carefully as at the moment of the placing of the covering pieces the layer of mortar or adhesive being used is soft and although the receiving lower surface or substrate may be completely smooth, the covering pieces may be somewhat tilted and not level, with the result of a faulty finishing of the covering. The mortar permits as well to absorb the irregularities of the substrate to be covered, although to a very limited extent.
At present, the leveling of the covering pieces has to be carried out by means of the traditional system, that is, after having applied the mortar or adhesive on the substrate aimed at receiving the covering pieces, the first covering element is placed and by means of a hand leveling tool its position is controlled without other assistance or means. If the covering piece does not appear to be properly leveled, its position is corrected by hammering the same with a rubber beater. This job is to be carried out repeatly for all the pieces of the covering so that it is a hard and annoying job as the operator has to work in an uncomfortable position during the whole working time, this being especially true in case of floor coverings.
In the following some embodiments of devices used so far for the alignment of covering pieces will be described.
One example of a device of this type is disclosed in the patent document U.S. Pat. No. 4,397,125 for a “System for aligning uneven thickness panel sections” which permits to obtain wall, floor or ceiling surfaces with a well aligned finishing on a plane, starting from covering pieces which do not have identical thickness, describing a device with a back plate which has a hole in which a screw is directly secured or on a protruding wing, with latching means for said screw; a back pressure plate being located in the back portion of the device, being pushed against the back plate by a nut or a wing nut engaged on said screw, to retain the adjacent covering pieces or panels by its borders. This system suffers from the inconvenience that the threaded screw and nut parts may be soiled with the mortar or adhesive being therefore difficult its withdrawal later on. Furthermore the metal parts and the screw may force to permit very substantial separations for which reason the system is more adequate for the placing of stone pieces on a wall with substantial separations between one another than for the placing of thin pieces for covering a substrate.
It is also known that the U.S. Pat. No. 5,675,942 “Wall panel alignment device and spacer” describes a similar device which is comprised of a base plate with a blocking shaft, a blocking plate and a latching element to keep the front and back sides of a couple of panels with similar thickness located on a wall in sideways alignment, while the adhesive applied to the panels solidifies, providing a smooth front surface. The base plate includes a lateral surface to hold the pair of panels in a common lateral back plane. The latching means is incorporated in the blocking plate to be engaged in the shaft by means of complementary toothed means which keep said latching element blocked in its place in respect of the base plate in the assembly of panels. The system for the engagement between the latching element and the shaft, in the way of a toothed belt, may be easily and directly located, for instance by hand or by means of a tool like those used for fitting clamps. However, to ensure that the sufficient alignment pressure may be carried out, the teeth have substantial dimensions and the pitch separating them is also sizeable. This purports that the adjustment of the alignment can not be carried out with the sufficient precision in the advance movement and with the sufficient pressure, as the engagement between the blocking plate in a given tooth of the toothing may finally be somewhat loose and the gearing with the next tooth can not be obtained or the pressure may be excessive, this resulting in a faulty assembly.
US patent applications US2006/0185269 y US2006/185319 both for “Tile alignment and leveling device and method for using the same” describe a device for the alignment and leveling of tiles on floors, ceilings and other substrates, which device has an upper plate with multiple separating wings and a lower plate. Both plates are combined by means of a post or shaft which extends from the lower plate going trough the upper plate so that the upper plate is movable along said post. In its use the device is located between adjacent tiles so that the upper and lower plates hold the adjacent tiles at the desired height while the mortar or adhesive solidifies. For the securement of the upper plate on the post in an adequate position a metal insert is used for its sideways introduction, engaging in one of the multiple notches which have been made crosswise in said post, this not permitting to regulate the pressure in a progressive and precise way as said notches are substantially separate between each other, so they don not permit a progressive introduction.